The proposed research will contribute to our understanding of growth cone mobility, and are well described and focused. The first objective of this proposal is to examine whether inhibition of myosin Ibeta using the CALI technique alters Myosin II atpase activity and mobility. The experiments are straight forward and important. The second observation will use the same micro-CALI techniques used to successfully investigate the roles of myosin V and myosin 1beta in filopodia. These experiments are important, and well described.